Cushion body structure comfortable to sit

ABSTRACT

In a cushion body structure of a car seat, which is made by fastening a skin material to a cushion material by using a planar fastening material, an impregnation layer made of a foamed body is not produced. In the cushion body structure, a planar fastening body (4) is integrally molded with a cushion material by shielding and clamping walls (22, 23) for preventing entry of a foaming solution in a molding die (20) of the cushion material (2,3), so that an opening is provided between the periphery of the planar fastening body and the side (3) of the cushion material, and a non-impregnation layer (7) is formed in the periphery.

TECHNICAL FIELD

The present invention relates to a cushion body structure of a car seatand in particular, relates to a cushion body structure that iscomfortable to sit on, in which a car seat is made by connecting a skinmaterial to a cushion material through a planar fastening body having animpregnation layer which avoids a feeling of hard and physicaldiscomfort on the periphery of the surface fastening body.

BACKGROUND OF THE ART

Several methods for attaching a cushion material (a foamed body)structure to a body portion of a car seat with a skin material attachedon its surface have been known and used in public, specifically as amethod of attaching a skin material to the cushion material in a concavesurface shape to secure the concave surface shape of a seating part ofthe seat. In the prior art, a method of adhering a whole back surface ofthe skin over a surface of the cushion material and a method such as anintegral molding method of injecting urethane into a cushion materialmolding die by setting a skin material therein have been often used.However, in either method, their own production systems for carrying outsuch methods are required, and it is difficult to install such systemsin a continuous assembly line, thereby increasing the cost fortransferring and manipulating materials. Also, such a method in theprior art is a mass production system and it is thus required tomaintain its operation rate. However, it is difficult to control avolume corresponding to a variation of the production rate. Thus, such aproduction method results in low productivity and causes a rise in cost.In order to avoid such disadvantages, a planar fastening material isused for attaching a surface material on cushioning material. Thisplanar fastening material is called a planar fastener or planarfastening material. The planar fastening material is a knitted ortextile base sheet containing a large number of hooked or ting-shapedsmall protrusions thereon. The hooked or ring-shaped small protrusionscan be fixed to the skin by fastening to the back surface of the skinmaterial and is found to be superior for its separating or shearing andattaching properties. However, if this planar fastening material is usedfor an integral molding in a cushion material molding die, in contrastwith an advantage of means for fastening a skin material which is lowcost, a disadvantage results which is an impregnation and hardening ofthe solution of the cushion material to a supporting material of theplanar fastening material is caused. Specifically, while it is desirableto attach the side end of the planar material with a space which isslightly apart from the side portion of the cushion material, a hardimpregnation layer is formed by impregnation of the solution of thecushion material into the planar fastening body, in particular, theperiphery of the supporting material adjacent the space. Thisimpregnation layer makes a feeling of physical discomfort for a personwho sits thereon because it can be felt through a skin covering thecushion material and also it can be felt by touching and moving his orher body thereon.

Therefore, an object of the present invention is, in a cushion bodystructure of a car seat which is made by fastening a skin material to acushion material through a planar fastening body connected by asupporting material having a constant thickness to a back surface of aplanar fastening material, to provide a cushion body structure of a carseat comfortable to sit upon which is made by forming a nonimpregnationlayer which does not absorb a foamed solution of the cushion material inthe periphery of the planar fastening material and the supportingmaterial positioned on its back surface.

DISCLOSURE OF THE INVENTION

For this, the present invention realizes a cushion body structure havinga planar fastening body by using a molding die which is divided into anarea for mounting the planar fastening body by a wall for preventingentry of the solution of the cushion material. The wall for preventingthe entry is preferably comprised of a vertical wall having a lengthsufficient to obtain the thickness of the planar fastening body and ahooked portion bending inwardly from its tip and is provided verticallyin the periphery of the area mounting the planar fastening body of amolding die, in particular, in both sides. By this, although the planarfastening body which is integrally molded with the cushion material hasan opening between the side portion of the cushion material and it, theside end of the planar fastening body is formed as a non-impregnationlayer which does not lose its softness.

The thickness of the supporting material constituting the planarfastening body, which is preferably made of a slab-urethane, is notspecially limited and is 5-15 mm and preferably 10 mm thickness. Thewall for preventing the entry is preferably made by having a lengthobtaining such a thickness and the hooked portion thereon.

In practice, the planar fastening body is mounted in a whole portion ofthe seat or an area corresponding to a least the center portion, so thatthe wall for preventing the entry is provided vertically in both sidesof the area. A front end and a rear end of the planar fastening bodycrossing between both sides is shaped by directly contacting the bodyportion of the cushion material and impregnation. If the impregnation ofthe solution of the body portion of the cushion body is too large in thefront end and the rear end, a similar wall for preventing the entry maybe provided in a position dividing the front end and the rear end of theplanar fastening body, but generally such can be done by walls forpreventing entry at the front and rear ends which are thin and have asmall height.

DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional end view showing a section of a cushion bodystructure having a good feeling for sitting, according to the presentinvention.

FIG. 2 is a fragmentary enlarged sectional end view of a molding die formolding a cushion body basically similar to a cushion body shown in FIG.1.

FIG. 3 is a differential sectional view of a molding die causing anonconformity in the art.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to the drawings, an embodiment of the present invention isdescribed. In addition, while the embodiment is illustrated only by anexample providing a non-impregnation layer in both side ends of theplanar fastening body, as mentioned above, it will be easily understoodthat such may be provided in the front and rear ends. A cushion body 1of the present invention has a planar fastening body 4 connected to acushion material body portion 2, as shown. A car seat is completed bycovering with a skin material 11 shown by a dotted line on the cushionbody 1. On both sides of the cushion material body portion 2 the sideportions 3 are highly raised to structure a bucket shaped seat. Theplanar fastening body 4 is preferably a lamination layer made by bondingor fusing a slab-urethane as the supporting material 6 to the planarfastening material 5 such as a planar fastener as mentioned later. Whilethere is a space (an opening) 10 between the cushion material sideportions 3, 3 in both side ends of the planar fastening body 4, anon-impregnation layer 7 which is not impregnated with the foamedsolution of the cushion material is formed in each end. Thus, a personwho sits thereon does not feel a feeling of hard and physical discomfortas is experienced in a cushion body forming an impregnation layeraccording to the prior art.

Describing a technique for integrally molding a planar fastening body ofthe prior art to a cushion body with reference to FIG. 3, a planarfastening body 14 is mounted on a bottom surface 17 of a lower die of amolding die. This planar fastening body 14 is substantially the same asthe planar fastening body of the present invention and is laminated of aslab-urethane as a supporting material 16 on a back surface of a planarfastening material 15. The planar fastening material 14 is mounted in apredetermined area on the bottom surface 17 and its end is typicallystopped by a stopper 18 to bear an injection of the foamed solution ofthe cushion material. However, if the foamed solution is injecteddownwardly in this state, a part of it will impregnate through the sideend of the supporting material (a slab-urethane) 16 so that a hardimpregnation layer 19 is formed. The impregnation layer 19 is formedalong both side portions of a seating surface of a seat and causes afeeling of hard and physical discomfort when a person who sits thereontouches it.

Accordingly, in the present invention, in order to mold a cushion bodystructure for an excellent seat for comfortable sitting without formingsuch an impregnation layer, the planar fastening body 4 is integrallymolded with the cushion body 1 by using a molding die as shown in FIG.2. That is, a lower die 20 of the molding die of the present inventionprovides a vertical wall 22 for preventing the entry of a foamedsolution in a position which divides an area mounting the planarfastening body 4 in substantially the center of its bottom surface 21.In addition, while the bottom surface 21 of the die shown in FIG. 2represents a planar surface, it can be readily understood to design acurved surface shape corresponding to a three-dimensional curved surfaceshape shown in FIG. 1. Each wall 22 for preventing the entry dividingthe area mounting the planar fastening body has a hooked portion 23inwardly bent at the tip of the vertical wall 22. The length of thevertical wall 22 to the hooked portion is sufficient to obtain thethickness of the planar fastening body 4 and is typically 5-15 mm andpreferably 10 mm. By setting the planar fastening body 4 in such a wall22 for preventing the entry, injecting the solution of the urethane (notshown) downwardly from the upper portion of the molding die, whilesealing the upper die and then foaming, the planar fastening body 4 ispressurized on the bottom surface 21 of the die and is connected to thecushion material body 2. The expanding foamed solution cannot enter theside end of the planar fastening body 4, thereby forming anon-impregnation layer 7 therein. As a specific embodiment, in order toform a seat shape having a three-dimensional curved surface as shown inFIG. 1 corresponding to a figure of a person who sits on a seat, theplanar fastening body 4 is made of the planar fastening material 5 (aplanar fastener commercially sold by a company named KURARE Inc.) and aslab-urethane foam 6 as the supporting material (the thickness is 5-15mm, and the density is 0.018 g/cm³ -0.040 g/cm³) having its appropriatethickness and density selected according to the feeling for sitting andthe curved surface shape. In practice, in a seat shape having the depthof the curved surface of 10 mm, the planar fastening body 4 is made byfusing and laminating the supporting material of urethane foam having athickness of 10 mm and a density of 0.034 g/cm³ to the planar fasteningmaterial used. Also, according to the amount of curvature of a seat, theperiphery of the planar fastening body 4 forms a space 10 apart 5-20 mmfrom the side 3 of the cushion material so that sitting thereon is morecomfortable and the impregnation layer is not produced.

As mentioned above, in the present invention, the planar fastening bodyis integrally molded by shielding and clamping a wall for preventingentry of a foaming solution in a molding die of the cushion material, sothat a cushion body structure which does not form an impregnation layerin the periphery of the planar fastening body and is soft and has goodand uniform properties is realized. While the planar fastening body isan excellent means for mechanically connecting the skin material withthe cushion material, by using this, if a hard impregnation layer is notproduced in the periphery of the planar fastening body in the art, useof the planar fastening body can be broadly employed, and a high-qualitycar seat can be provided rapidly and economically without greatlyincreasing cost.

We claim:
 1. A cushion structure for a vehicle seat comprising, a foamedcushion body having a main portion and upwardly extending side portions,said cushion body having a rising portion to form spaces between saidrising portion and said side portions, a planar fastening body having asupport layer having a constant thickness overlying said rising portionof said main portion of said cushion body and disposed between said sideportions, a skin material positioned over said planar fastening body andsaid side portions and attached to said planar fastening body, theperiphery of said fastening body projecting over said spaces to saidside portions, an impregnation layer formed between and integrating saidsupport layer and said rising portion of said cushion body, and anon-impregnation layer in said periphery of said fastening body beingnot impregnated by said foamed cushion body.
 2. A cushion structureaccording to claim 1, wherein said periphery of said fastening body isnot in contact with said side portions.
 3. A cushion structure accordingto claim 1, wherein said non-impregnation layer is formed by theexistence of an inverted L-shaped wall preventing entry of foamablesolution which is vertically located in a position which divides an areamounting the planar fastening body in a mold for the cushion body.
 4. Acushion structure according to claim 1, wherein said impregnation layeris in said support layer of said planar fastening body.
 5. A vehicleseat cushion comprising, a foamed cushion body having a central bodyportion and raised upper side portions, a laminated planar fasteningbody having a lower support layer and an upper fastening material with alower surface engaging said central body portion and ends disposedproximate to said raised upper side portions, an impregnation layer insaid support layer formed between and integrating said lower surface ofsaid planar fastening body and said central body portion of said foamedcushion body, a non-impregnation layer in said ends of said planarfastening body and extending into said lower surface of said planarfastening body, and a skin material positioned over said planarfastening body and said upper side portions of said foamed cushion body.6. A vehicle seat cushion according to claim 5, wherein said ends ofsaid planar fastening body are spaced from said raised upper sideportions of said foamed cushion body.
 7. A vehicle seat cushionaccording to claim 5, wherein a space is formed between saidnon-impregnation layer and said raised upper side portions and saidcentral body portion of said foamed cushion body.
 8. A vehicle seatcushion according to claim 5, wherein said skin material is attached tosaid planar fastening body.
 9. A vehicle seat cushion according to claim5, wherein said non-impregnation layer extends about the entireperiphery of said planar fastening body.
 10. A vehicle seat cushioncomprising, a cushion body having a central body portion and raisedupper side portions, a planar fastening body having a lower supportlayer with a lower surface affixed to a portion of said central bodyportion and ends disposed proximate to said raised upper side portions,a non-impregnation layer in said ends of said planar fastening body, anda skin material positioned over said planar fastening body and saidupper side portions of said cushion body, wherein said planar fasteningbody is attached to said cushion body by the process of:positioning saidplanar fastening body in a mold having a seating surface on an innersurface thereof, pouring a foamable composition for forming said cushionbody into said mold, closing the mold, and foaming the foamablecomposition to form said cushion body and to impregnate said lowersurface of said planar fastening body, while precluding impregnation ofsaid ends of said planar fastening body by positioning walls in saidmold interposed between said ends of said planar fastening body and saidfoamable composition.
 11. A vehicle seat according to claim 10, whereinthe process for attaching said planar fastening body to said cushionbody further comprises the step of precluding impregnation of said endsof said planar fastening body and a portion of said lower surface ofsaid planar fastening body by positioning walls interposed between saidends of said planar fastening body and a portion of said lower surfaceof said planar fastening body and said foamable composition.